A Troponin of 26.2: Ventricular Tachycardia Storm at the Marathon Finish Line
A 47-year-old highly active female with past medical history of rheumatoid arthritis (RA) presented with lightheadedness and diaphoresis after crossing the finish line at the local marathon. She was found to be in polymorphic ventricular tachycardia (VT) and was shocked three times in the field, intermittently losing consciousness but maintaining pulses. On arrival at the hospital, she was unresponsive and remained in VT for 12 minutes despite multiple defibrillations and intravenous administration of amiodarone, lidocaine, metoprolol, and magnesium. Ultimately, her rhythm degenerated into ventricular fibrillation, terminating after sedation and intubation, with brief requirement of cardiopulmonary resuscitation (CPR).
She had three prior episodes of exercise-associated syncope/presyncope (notably two were also post-marathon), with reportedly normal stress testing. Her only medication is methotrexate for RA. There was no history of smoking, excessive alcohol use, drug use, or supplement use, and she disclosed no family history of cardiovascular disease or sudden cardiac death (SCD).
Her post-arrest 12-lead electrocardiogram (ECG) is shown in Figure 1. Echocardiogram showed a non-dilated left ventricle (LV) with an ejection fraction (LVEF) of 25%; global hypokinesis with the most significant wall motion abnormalities in the anterior, anterolateral, and apical walls; normal right ventricular size with mildly reduced function; and no significant valvular disease. Labs were notable for an initial troponin-I of 2.0 ng/ml with a peak of 26.2 ng/ml, normal electrolytes, transaminitis and transient acute kidney injury post-arrest, total cholesterol of 136 mg/dl, and low-density lipoprotein cholesterol (LDL-C) of 45 mg/dl.
Coronary angiography was performed (Video 1 and Figure 2). There was no evidence of ruptured plaque and only mild non-obstructive atherosclerotic disease. There was dampening in the aortic pressure upon engagement of the left main artery. Cardiac magnetic resonance imaging (MRI) was subsequently performed 2 days following arrest (Figure 3). Transthoracic echocardiography performed 3 days after cardiac arrest demonstrated an LVEF of 50% with near resolution of wall motion abnormalities. ECG prior to discharge is shown in Figure 4.
What is the correct diagnosis?